In the current state of the gas fireplace industry, gas fireplaces are typically purchased and installed by developers and builders for incorporation into residential units which are later sold to a customer or which may be presold. Not surprisingly, the developer and builder is generally interested in installing the least expensive gas fireplace available. It is not uncommon for the ultimate purchaser of the home to be dissatisfied with the look of the unit installed by the builder. Often the homeowner will seek to replace the unit for a different configuration of gas fireplace. For example, a homeowner may prefer a particular style of decorative fireplace over the style which was installed by the builder. Similarly, the homeowner may prefer a heat efficient gas fireplace rather than a decorative gas fireplace. Typically, accommodating the homeowner's desires requires removal of the entire gas fireplace structure including the burners and the associated shell and fire box and ducting connectors. This is time-consuming, expensive and inconvenient.